학술논문

A miniaturized 3 /spl times/ 3-mm SAW antenna duplexer for the US-PCS band with temperature-compensated LiTaO/sub 3//sapphire substrate
Document Type
Conference
Source
IEEE Ultrasonics Symposium, 2004 Ultrasonics Symposium Ultrasonics Symposium, 2004 IEEE. 2:954-958 Vol.2 2004
Subject
Signal Processing and Analysis
Fields, Waves and Electromagnetics
Components, Circuits, Devices and Systems
Engineered Materials, Dielectrics and Plasmas
Surface acoustic waves
Thermal conductivity
Bonding
Temperature
Frequency
Dielectric substrates
Insertion loss
Dielectric constant
Packaging
Personal communication networks
Language
ISSN
1051-0117
Abstract
This paper describes a temperature-stable and miniaturized SAW antenna duplexer for the 1.9 GHz US-PCS band that uses a temperature-compensated 42/spl deg/ Y-X:LiTaO/sub 3//sapphire bonded substrate. In this duplexer, the temperature coefficient of frequency is reduced to half or two-thirds of that of a conventional LiTaO/sub 3/ substrate. Also, it is shown that our new duplexer has a smaller insertion loss and offers sufficient power durability. These improvements are mainly due to the characteristics of sapphire, such as its larger thermal conductivity and smaller dielectric constant. Furthermore, the performance of our SAW duplexer is compared with that of two kinds of BAW duplexers, which are competitive technologies. As a result, it is shown that our newly developed SAW duplexer offers equal or better performance in a smaller package. This implies that our SAW duplexer is the best and the smallest PCS duplexer.